Oscar Perez is one of two inmates housed at different Indiana prisons who used cellphones smuggled in by guards to run a drug ring that distributed methamphetamine and heroin, according to a federal indictment that charges 40 people in connection with the scheme. (AP Photo/Elkhart County Sheriff’s Department)(AP)Former prison officer Jon Dobbins, who worked at the Wabash Valley Correctional Facility in southwestern Indiana, was indicted along with 39 others in the prison drug ring Wednesday. (AP Photo/Sullivan County Sheriffs Department, HO)(AP)

INDIANAPOLIS — A drug ring that two Indiana inmates allegedly ran behind bars using cellphones to orchestrate drug purchases and sales shows the risks posed by the widespread problem of phones being smuggled into the nation’s prisons, officials said.

Contraband cellphones are so common that even Charles Manson, one of the nation’s most notorious inmates, has been caught at least twice with cellphones in the California prison where he’s serving a life sentence for his role in the 1969 murders of seven people.

Texas state Sen. Joan Huffman said about 2,000 contraband cellphones are seized each year from Texas prisons, frustrating prison officials and law enforcement officers because it allows inmates to circumvent prison-monitored land lines.

“There’s been criminal activity being orchestrated from prison as well as actual threats to individuals,” said the Houston Republican who’s vice chairwoman of the Texas Senate’s Criminal Justice Committee. “There have even been instances where they’ve tried to contact witnesses or victims with threats, calls about changing their testimony.”

A federal indictment unsealed Wednesday in Indianapolis charges two inmates at different Indiana prisons — Oscar Perez, 26, and Justin Addler, 28 — with using cellphones smuggled to them by prison guards to run a ring that moved heroin, methamphetamine and other drugs in cities around the state.

Perez, formerly of 615 W. Franklin St., Elkhart, is in prison for murder, attempted murder and criminal gang activity for his involvement in a gang shooting that killed one teen and wounded another in February 2006. He was originally sentenced to 85 years in prison.

A total of 40 people were indicted on drug-related charges, including distribution of heroin, methamphetamine, PCP and other drugs. Two of those individuals remained at large Thursday, said FBI Special Agent Wendy Osborne.

The indictment alleges that Perez, who’s serving time for murder and criminal gang activity, and Addler, who was convicted on drug and gun charges, instructed their co-defendant on the details of transferring money for drug purchases and how and where to sell the narcotics.

Some of those calls were allegedly three-way calls, including one between Perez, Addler and a third man in which they discussed “pooling their financial resources” to get a discount on heroin, the indictment says.

In one May 2012 call, Addler stayed on the phone with a woman “throughout the duration” of a drug deal as she sold about 20 grams of heroin at a truck stop in Crawfordsville, Ind., for $2,500, the document states.

Although the indictment alleges multiple prison guards smuggled cellphones into state prisons as part of the scheme, it names only one prison guard, 37-year-old Jon Dobbins.

Dobbins, who worked at the Wabash Valley Correctional Facility, is accused of delivering a package containing 13 grams of pure meth and a cellphone into the southwestern Indiana prison in July, allegedly for use by an inmate.

Prison spokesman Rich Larsen said Dobbins, who was arrested in July on state charges that preceded the federal charges, was fired July 15 after working at the prison for 16 years.

Federal prosecutors declined Thursday to comment on the indictment, including whether additional people, including prison guards, might be charged.

Indiana Department of Correction spokesman Doug Garrison said hundreds of cellphones are seized each year from inside Indiana’s prisons and many more elude detection.

“Despite our best efforts, sometimes it happens,” he said.

Garrison said many are thrown over fences or smuggled in by visitors, who sometimes conceal them in their body cavities — a technique that’s difficult to detect even with screening procedures.

Chris Burke, a spokesman for the Federal Bureau of Prisons, said the federal agency is reviewing new technology that might be able to detect contraband cellphones at its 117 prisons around the country.

“We have serious concerns about their introduction into any of our facilities,” he said.

Huffman, the Texas state senator, said many lawmakers in her state would like to use new technologies to jam cellphone signals in Texas’ prisons, but that is currently forbidden by the Federal Communications Commission.

“That would nip the problem in the bud, because it’s almost impossible to keep them out of our prisons,” Huffman said. “It’s very frustrating to us that we can’t have the local control, state control, to regulate our prisons the way we’d like to see them regulated.”